How do I schedule a batch update to a collection in my Firebase Firestore database using Cloud Functions?

Question

I am new to JS and Cloud Functions and I would like to perform an update to a collection in my Firestore database every day at midnight. I have a collection appointmentTimes with a boolean field available and I want to reset this to true every day at midnight. So far I've tried using the following:

const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp();

exports.resetAppointmentTimes = functions.pubsub.schedule('0 0 * * *').onRun((context) => {
    const appointmentTimesCollectionRef = db.database().collection('appointmentTimes');
    appointmentTimesCollectionRef.get().then(querySnapshot => {
        if (querySnapshot.empty) {
            return null;
        } else {
            let batch = db.database().batch();
            querySnapshot.forEach(doc => {
                batch.update(doc.ref, { available: true });
            });
            return batch.commit();
        }
    }).catch(error => { console.log(error); });
})

Thank you for any input/suggestions!

Answer 1

It is not clear what is db.database(). You should use the Admin SDK and call admin.firestore() to get a Firebase App instance. also, you need to return the Promises chain (watch the 3 videos about "JavaScript Promises" from the Firebase video series: https://firebase.google.com/docs/functions/video-series/ for more details).

The following should do the trick:

const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp();

const db = admin.firestore();

exports.resetAppointmentTimes = functions.pubsub.schedule('0 0 * * *').onRun((context) => {
    const appointmentTimesCollectionRef = db.collection('appointmentTimes');
    return appointmentTimesCollectionRef.get()  // See the return here
    .then(querySnapshot => {
        if (querySnapshot.empty) {
            return null;
        } else {
            let batch = db.batch();
            querySnapshot.forEach(doc => {
                batch.update(doc.ref, { available: true });
            });
            return batch.commit();
        }
    })
    .catch(error => { 
        console.log(error); 
        return null;
    });
})

Answer 2

You can use node-schedule like a cron file

var schedule = require('node-schedule');

var j = schedule.scheduleJob('0 0 0 * * *', function(){
    const appointmentTimesCollectionRef = db.database().collection('appointmentTimes');
appointmentTimesCollectionRef.get().then(querySnapshot => {
    if (querySnapshot.empty) {
        return null;
    } else {
        let batch = db.database().batch();
        querySnapshot.forEach(doc => {
            batch.update(doc.ref, { available: true });
        });
        return batch.commit();
    }
}).catch(error => { console.log(error); });
});